28 GENERAL ANATOMY. 



where throughout the body, serving partly as a uniting, partly as an envelop- 

 ing medium for the organs and their elements. It possesses a fibrous inter- 

 lacement, is very elastic and translucent, and by boiling is metamorphosed 

 into Gelatin (?). 



Structure. Uniting tissue consists of long and probably solid fibres, which, 

 held together by amorphous blastema, and generally united into white bundles, 

 become transparent by acetic acid. Dark spiral filaments, which are not made 

 transparent by acetic acid, wind themselves in a serpentine arrangement about 

 each bundle, and are probably developed from nucleus fibres, just as those 

 of the first from fibres of the cell vesicle. 



29. We distinguish two kinds of uniting tissue : 



1. Amorphous. It is loose and fills up the intervals between the organs 

 and their parts, for example, between the lobes and lobules of the liver ; it 

 lies in great masses under the Cutis, and forms cells, in which air and fluid 

 may collect, or in which fat vesicles are deposited. Vessels and nerves 

 traverse it in larger or smaller numbers. Burdach calls the uniting tissue 

 which envelopes the exterior of organs atmospherical (thus the subcutaneous 

 areolar tissue), and that which enters into the organ parenchymatous. 



2. Figurate. It forms membranes, bladders, cords, and discs ; is fibrous, 

 and the more even and brilliant the thicker its tissue. Of it we may dis- 

 tinguish two kinds : 



a. Not contractile, uniting tissue (fibrous or tendinous). 



1. Tendons. They are very dense and strong, little elastic, and long 

 resist decomposition and chemical influences; they contain 0'02 water. 

 Where tendons pass over bones, a loose uniting tissue with coarse meshes 

 surrounds them (Synovial sheaths), in which a glairy clear fluid is contained 

 (Synovia). The tendons (sinews) are adherent to the muscular fibres, irom 

 which they are only prolonged, and to which they are firmly attached by 

 uniting tissue. 



2. Ligaments, ligamc.nta, are quite similar to tendons, but generally flat. 

 To this class belongs the round ligament (lig. feres), which assists in main- 

 taining the head of the femur in the acetabulum ; the membrana obturat. of 

 the thyroid or oval foramen of the oss innominatum and the memb. interrossea 

 form a transition towards the fibrous membranes. The elastic and inter- 

 articular ligaments of the vertebral column do not belong to this class. (See 

 Syndesmology). 



3. Ligamentary discs. [Interarticular cartilages, Glenoid ligaments.] 

 Very strong, and therefore ibrmerly enumerated with the cartilages which, 

 moreover, are less elastic. They are intended to prevent the pressure of 

 two cartilaginous surfaces upon one another, on which account they are also 

 invested with Synovial sheaths. Tendinous fibres, which pass off from the 

 borders, are attached to the articular capsules or cartilages. 



Ligamentary Discs are found in the articulations of the jaw and knee ; in 

 the superior eyelid (tarsus, the so-called cartilage), around the articular fossae 

 of the acetabulum and scapula (labra cartilaginea). 



4. Fibrous membranes. To this class belong: 



The external coverings or case of many viscera, serving as a defence for 

 the Parenchyma, or for the attachment of muscles, e. g., the Sclerotica of the 

 eye, the Jilbuginea of the testis, Dura Mater of Brain and Spinal cord, the 

 covering of the pericardium, of the kidneys, ovaries, spleen, clitoris, and 

 urethra. 



The tendons of the muscles attached are interwoven with them. Their 

 tissue consists of separate fibres, or of more or less interlaced bundles. They 

 are covered with epithelium. 



